The invention concerns improvements in the adjustment of tools of forging presses.
In forging presses, in particular horizontal transfer presses, a workpiece is put into the desired shape by a shaping operation, by a procedure whereby the workpiece is so firmly pressed between a fixed die and a movable ram or punch that the desired shaping effect takes place.
In such an arrangement, in operation of the machine, the ram or punch is not generally moved to a position in which it bears against the die, but is only moved to a so-called closing height spacing which is naturally crucial in terms of the result of the shaping procedure.
By virtue of fluctuations in the dimensions of the blank, thermally induced expansion of the machine as a result of on-going operation thereof and so forth, that closing height spacing must be settable, that is to say subsequently adjustable.
As the closing height spacing is a spacing which is measured in the longitudinal direction, that is to say in the direction of the pressing stroke movement, that effect was hitherto achieved by providing a setting device on the side of the movable ram or punch, that is to say on the impact side of the machine. The setting device pushes a setting wedge member in the wedge direction, transversely with respect to the longitudinal direction, to a greater or lesser distance between the movable ram or punch and the remainder of the movable carriage carrying the ram or punch.
In that way, the stroke movement, which is always identical, in regard to the drive of the carriage is not altered, on the side of the ram or punch, in terms of the stroke distance, but it is in fact altered in terms of the longitudinal position at the two motion-reversal points, and that also means that the closing height spacing relative to the stationary die is altered.
A structure of that kind is described for example in DE 197 22 229 A1, wherein the setting device is driven by motor means.
A disadvantage however is that the entire setting device is disposed in the moved part of the machine, the impact side, and not in the stationary support side. That is a disadvantage by virtue of the high acceleration forces involved (about 300 stroke per minute) while in addition there is also the disadvantage that for repair operations, not only is it necessary for the machine to be stopped, but under some circumstances it is also necessary for the complete carriage to be dismantled, which gives rise to major losses in production.